1. Field of the Invention
The invention relates to benzene, pyridine, and pyridazine derivatives and more specifically to such compounds that are useful in the treatment and/or prevention of diseases and/or conditions related to cell proliferation, such as cancer, inflammation and inflammation-associated disorders, and conditions associated with angiogenesis. Compounds of the invention are also useful in the treatment and/or prevention of infectious diseasaes, in particular, fungal infections.
2. Description of the Related Art
Cancer is characterized by abnormal cellular proliferation. Cancer cells exhibit a number of properties that make them dangerous to the host, typically including an ability to invade other tissues and to induce capillary ingrowth, which assures that the proliferating cancer cells have an adequate supply of blood. A hallmark of cancerous cells is their abnormal response to control mechanisms that regulate cell division in normal cells and continue to divide until they ultimately kill the host.
Angiogenesis is a highly regulated process under normal conditions, however many diseases are driven by persistent unregulated angiogenesis. Unregulated angiogenesis may either cause a particular disease directly or exacerbate an existing pathological condition. For example, ocular neovascularization has not only been implicated as the most common cause of blindness, but also is believed the dominant cause of many eye diseases. Further, in certain existing conditions, for example arthritis, newly formed capillary blood vessels invade the joints and destroy cartilage, or in the case of diabetes, new capillaries formed in the retina invade the vitreous, bleed, and cause blindness. Growth and metastasis of solid tumors are also dependent on angiogenesis (Folkman, J., Cancer Research, 46, 467-473 (1986), Folkman, J., Journal of the National Cancer Institute, 82, 4-6 (1989). It has been shown, for example, that tumors which enlarge to greater than 2 mm must obtain their own blood supply and do so by inducing the growth of new capillary blood vessels. Once these new blood vessels become embedded in the tumor, they provide a means for tumor cells to enter the circulation and metastasize to distant sites such as liver, lung or bone (Weidner, N., et al., The New England Journal of Medicine, 324(1), 1-8 (1991). Under conditions of unregulated angiogenesis, therapeutic methods designed to control, repress, and/or inhibit angiogenesis could lead to the abrogation or mitigation of these conditions and diseases.
Inflammation is related to a variety of disorders such as pain, headaches, fever, arthritis, asthma, bronchitis, menstrual cramps, tendonitis, bursitis, psoriasis, eczema, burns, dermatitis, inflammatory bowel syndrome, Crohn's disease, gastritis, irritable bowel syndrome, ulcerative colitis, vascular diseases, Hodgkin's disease, sclerodoma, rheumatic fever, type I diabetes, myasthenia gravis, sarcoidosis, nephrotic syndrome, Behcet's syndrome, polymyositis, hypersensitivity, conjunctivitis, gingivitis, post-injury swelling, myocardial ischemia, and the like.
Heat-shock protein 90 (HSP-90) is a cellular chaperone protein required for the activation of several eukaryotic protein kinases, including the cyclin-dependent kinase CDK4. Geldanamycin, an inhibitor of the protein-refolding activity of HSP-90, has been shown to have antiproliferative and antitumor activities.
HSP-90 is a molecular chaperone that guides the normal folding, intracellular disposition and proteolytic turnover of many key regulators of cell growth and survival. Its function is subverted during oncogenesis to make malignant transformation possible and to facilitate rapid somatic evolution, and to allow mutant proteins to retain or even gain function. Inhibition of HSP-90 will slow those process thus has potential therapeutic use (Whitesell L, Lindquist, S L, Nature Rev. Cancer, 2005, 10, 761-72).
Ansamycin antibiotics, e.g., herbimycin A (HA), geldanamycin (GM), and 17-allylaminogeldanamycin (17-AAG) are thought to exert their anticancerous effects by tight binding of the N-terminus pocket of HSP-90, thereby destabilizing substrates that normally interact with HSP-90 (Stebbins, C. et al. Cell 1997, 89, 239-250). This pocket is highly conserved and has weak homology to the ATP-binding site of DNA gyrase (Stebbins, C. et al., supra; Grenert, J. P. et al. J. Biol. Chem. 1997, 272, 23843-50).
In vitro and in vivo studies have demonstrated that occupancy of this N-terminal pocket by ansamycins and other HSP-90 inhibitors alters HSP-90 function and inhibits protein folding. At high concentrations, ansamycins and other HSP-90 inhibitors have been shown to prevent binding of protein substrates to HSP-90 (Scheibel, T. H. et al. Proc. Natl. Acad. Sci. USA 1999, 96, 1297-302; Schulte, T. W. et al. J. Biol. Chem. 1995, 270, 24585-8; Whitesell, L., et al. Proc. Natl. Acad. Sci. USA 1994, 91, 8324-8328). Ansamycins have also been demonstrated to inhibit the ATP-dependent release of chaperone-associated protein substrates (Schneider, C. L. et al. Proc. Natl. Acad. Sci., USA 1996, 93, 14536-41; Sepp-Lorenzino et al. J. Biol. Chem. 1995, 270, 16580-16587). In either event, the substrates are degraded by a ubiquitin-dependent process in the proteasome (Schneider, C. L., supra; Sepp-Lorenzino, L., et al. J. Biol. Claim. 1995, 270, 16580-16587; Whitesell, L. et al. Proc. Natl. Acad. Sci. USA 1994, 91, 8324-8328). HSP-90 substrate destabilization occurs in tumor and non-transformed cells alike and has been shown to be especially effective on a subset of signaling regulators, e.g., Raf (Schulte, T. W. et al., Biochem. Biophys. Res. Commun. 1997, 239, 655-9 Schulte, T. W., et al., J. Biol. Chem. 1995, 270, 24585-8), nuclear steroid receptors (Segnitz, B.; U. Gehring J. Biol. Chem. 1997, 272, 18694-18701; Smith, D. F. et al. Mol. Cell Biol. 1995, 15, 6804-12), v-Src (Whitesell, L., et al. Proc. Natl. Acad. Sci. USA 1994, 91, 8324-8328) and certain transmembrane tyrosine kinases (Sepp-Lorenzino, L. et al. J. Biol. Chez. 1995, 270, 16580-16587) such as EGF receptor (EGFR) and HER2/Neu (Hartmann, F., et al. Int. J. Cancer 1997, 70, 221-9; Miller, P. et al. Cancer Res. 1994, 54, 2724-2730; Mimnaugh, E. G., et al. J. Biol. Clzem. 1996, 271, 22796-801; Schnur, R. et al. J. Med. Chenu. 1995, 38, 3806-3812), CDK4, and mutant p53. Erlichman et al. Proc. AACR 2001, 42, abstract 4474. The ansamycin-induced loss of these proteins leads to the selective disruption of certain regulatory pathways and results in growth arrest at specific phases of the cell cycle (Muise-Heimericks, R. C. et al. J. Biol. Chez. 1998, 273, 29864-72), and apoptosis, and/or differentiation of cells so treated (Vasilevskaya, A. et al. Cancer Res., 1999, 59, 3935-40). Inhibitors of HSP-90 thus hold great promise for the treatment and/or prevention of many types of cancers and proliferative disorders, and also hold promise as traditional antibiotics.
Inhibition of HSP-90 is also known to result in up regulation of the expression of the chaperone HSP70. HSP70 up regulation is considered to be of therapeutic benefit for treatment of a wide range of neurodegenerative diseases including, but not limited to: Alzheimer's disease; Parkinson's disease; Dementia with Lewy bodies; Amyotropic lateral scleriosis (ALS); Polyglutamine disease; Huntington's disease; Spinal and bulbar muscular atrophy (SBMA); and Spinocerebellar ataxias (SCA1-3,7). Therefore, the compounds described in the invention are of potential therapeutic use for treatment of such neurodegenerative diseases (Muchowski, P. J., Wacker J. L., Nat. Rev. Neurosci. 2005, 6, 11-22; Shen H. Y., et al. J. Biol. Chem. 2005, 280, 39962-9).
Inhibition of HSP-90 also has anti-fungal activity, both as a stand alone therapy and in combination with standard anti-fungal therapies such as the azole class of drugs. Therefore, the compounds described in the invention are of potential therapeutic use for treatment of fungal infections including, but not limited to, life threatening systemic fungal infections (Cowen, L. E., Lindquist, S., Science 2005, 309, 2185-9).
Inhibition of HSP-90 also has antimalarial activity; thus, inhibitors of this protein are useful as antimalarial drugs.
Therefore, there is a continuing need in the art for new methods of treating cancer, inflammation and inflammation-associated disorders, and conditions or diseases related to uncontrolled angiogenesis.